Feed lifting mechanism



May 29,1962

G. e. MENKEL FEED LIFTING MECHANISM Filed Feb. 3, 1959 United States Patent York Filed Feb. 3, 1959, Ser. No. 790,842 9 Claims. (Cl. 18-19) The present invention relates to machines for forming or shaping sheet materials and, more particularly, to a feed mechanism for use in such machines.

In Middleton Patent 2,522,956, issued September 19, 1950, there is described an eflicient and highly successful machine for rapidly forming shaped articles from thermoplastic sheet materials. In this machine, a web of thermoplastic material is advanced from a source of supply through a heating zone and a drawing or forming zone, the web, with the articles formed in the drawing or forming zone, thereafter being discharged from the machine. The present invention is concerned with an improvement in machines of this general type and, in pmticular, with a novel and improved feeding and discharge mechanism for the web of thermoplastic material.

In the feeding of sheet materials for drawing, a continuous web of material is intermittently withdrawn from a reel or spool and fed first through a heating zone where the web is conditioned for drawing and then. after a predetermined interval of time, is fed from the heating zone into a drawing or forming zone where it is held while the preconditioned web is formed into a desired shape. After the shape has been formed, the web, with the article formed therein, is removed from the machine. Forming may be accomplished by mating dies engaging the opposite sides of the preconditioned web or by a single die onto which the preconditioned web is formed by air pressure applied to the web opposite the die or by a vacuum applied by nozzles in the die which draw the preconditioned web into contact with the die. In order to prevent shrinkage in the sheet during heating and forming and to feed the web material from the supply roll or reel through the various zones, a gripping mechanism is usually provided at the marginal edges of the sheet. Machines of the foregoing type are high in speed and it is desirable to remove the formed web from the machine at a high speed without damage to the formed article.

It is also desirable that the mechanism for removing the formed web be relatively simple in construction and smooth in operation and that it afford quick withdrawal without damage to the formed web.

In accordance with the foregoing, it has been a principal object of the invention to provide a novel mechanism for releasing and removing shaped articles from a forming machine.

Another object of the invention has been to provide a releasing and removing mechanism for use with heated thermoplastic material which will allow release and removal of the shaped article at high speed.

A further object of the invention has been the provision of a release and removal mechanism in which the formed web may be withdrawn without damage.

Another object of the invention has been the provision of a mechanism of the foregoing type which is compact and affords positiv release and withdrawal.

Other and further objects, features and advantages of the invention will appear more fully from the following description.

Referring to the drawings:

FIG. 1 is a side elevation of the drawing press, partly in section, showing the release and removal mechanism of the invention.

FIG. 2 is an end elevation of the drawing press of FIG. 1.

3,936,336 Patented May 29, 1962 Referring now to the drawings, there is shown a press,

such as the press described in the aforementioned patent to Middleton, having a frame 10, provided with guides 12, 14, ahead plate 16 fixed to the upper ends of guides 12, 14, and a double acting cylinder 18, of conventional design, attached to the head plate 16. The cylinder 18 is provided with a piston, not shown, and piston rod 20 connected to plate 22 movable by the piston rod 20 on the guides 12, 14. A die 24 is fixed to the plate 22 for movement with said plate. A second die 26, in vertical alignment with the die 24, is fixed to the frame 10.

A support, generally designated 30, comprising two spaced parallel arms 32, 34, connected by a plate 36, is pivotally connected to the frame 10 by a shaft 38. Since the elements located on either side of the support 30 and connected to or associated with each of the arms 32, 34 are identical, only the arm 32. will be described in detail, it being understood, of course, where an element is described as connected to or associated with the arm 32, an identical element is connected to or associated with the arm 34.

A spool 40, carrying a supply of web material 42, is rotatably carried on a shaft 44 on a spool member 46 fixed to the arm 32, the support 30 being provided with web tensioning shafts 50, 52, and 54 rotatably supported on arm 32 by bearings 56, 57 and 58, respectively.

A rod 60 is pivotally connected at 62 to the arm 32 and projects through an opening 64 in an arm 66 attached to the plate 22, the rod 60 being provided at either side of the opening 64 with adjustable stops 68 and 70 for purposes more clearly pointed out herein-after. A guide 72 is fixed to the end of the arm 32 for movement through the opening 74 in the arm 76 attached to the frame 10, the guide 72 being provided with a shock absorber 8'0 of rubber or similar resilient material, between the arm 76 and the arm 32. Intermediate its ends, the arm 32 is provided with a material clamping or feeding mechanism, diagrammatically shown as 84 on the attached drawings which may be similar to that shown in the aforementioned Middleton patent or in my copending application, Serial No. 730,135 filed April 22, 1958, now Patent No. 2,961,- 137, the particular configuration of the material clamping or feeding mechanism forming no part of the instant invention.

In operation, a supply spool 49 of web material 42 is placed on the shaft 44 and is fed through the tensioning shafts Si), 52 and 54 into the material clamping or feeding mechanism 84. With the web material thus in place the machine is then started, the mechanism 84 feeding the web material from the spool 40 along the support 30. In the apparatus, as shown in the aforementioned Middleton patent, the web material 42 is first passed through a heating zone, not shown in the attached drawing, and is held for a predetermined interval of time in the heating zone until in desired condition for drawing. When in the desired condition, the web 42 is next fed by mechanism 84 into the area between the dies 24 and 26 which will be termed the drawing zone. When the web reaches the drawing zone the mechanism 84 again momentarily stops, the piston rod 20, actuated by the cylinder 18, forces the plate 22 and die 24 downward. As the plate 22 moves downward the arm 66 attached to the plate 22 contacts the stop 68 and, through the rod 60, forces the support 30 to pivot about the shaft 38, causing the free end thereof to move downward. The plate 22 and die 24 move downward until the web 42 contacts the upper surface of the lower die 26, at which time the die 24 contacts the thermoplastic web 42 and forces the web into the die 26 and forms the desired shape or article in the web material.

When the forming operation is completed, the double 3 acting cylinder 18 is reversed and the piston rod 20 moves the plate 22 and die 24 upward, Withdrawing the die 24 from the die 26. As the plate 22 moves upward the arm 66 attached to the plate 22 contacts the stop 70 on the rod 60 and, through the rod 69, pivots the support 30, lifting its free end. As the arm 30 rises, the web 42, with the shape or article formed therein, is withdrawn from the die 26 by the mechanism 84 attached to the support 30. With the web 42 and the shape or article formed therein clear of the die 26, the mechanism 84 is actuated and again feeds the web material, feeding the shaped or formed section of the web material 42 out of the drawing zone and away from the machine, and, at the same time, delivering the next preconditioned section of the thermoplastic web 42 into the drawing zone and the following section of web material into the heating or conditioning zone.

In the attached drawings, the die 26 is shown as female and the die 24 as male. It is to be understood that these dies may be reversed, in which instance the die 26 would be male and the die 24 female. With such an arrangement, the formed web 42 would be lifted off of the die 26 rather than out of such die as is the case where the die 26 is the female member.

Although the invention has been described in connection with two dies, it is to be understood that, rather than using two dies, a single die located on the frame 10 may be used. Where a single die is employed, air pressure may be used to form the thermoplastic web on the die. Such air pressure may be in the form of pressure applied to the top of the thermoplastic web, such as from suitable nozzles'carried on the head 22, or may be in the form of a vacuum applied beneath the thermoplastic web, such as from suitable nozzles located in the die 26. In either event, the die located on the frame may be either of male or female form. Where a single die and air pressure, whether in the form of pressure applied to the top or a vacuum applied beneath the web, are employed, the air supply may be controlled by a suitable valve actuated by the plate 22 as it moves vertically on the guides 12 and 14.

The advance of the web material through the heating and forming zones and the withdrawal of the formed material from the machine in an intermittent manner may be controlled in any convenient way, such, for example, as is described in the aforementioned Middleton patent.

While the invention has been described in connection with a specific embodiment thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. In a machine for forming thermoplastic web material having a source of supply of said web material, a frame, a die fixed to said frame, a feed mechanism for advancing said web material in a predetermined path through said machine whereby desired operations may be performed thereon, said feeding mechanism comprising means to engage said web material adjacent the edges thereof for advancing said web across said die, a support movably attached to said frame, said feeding mechanism being fixed to said support, and means to move said support and thereby said feeding mechanism and said web transverse to said predetermined path to engage said web material with said die and to disengage said web material from said die.

2. In a machine for forming thermoplastic web mate rial having a frame, a die fixed to said frame, means associated with said die for forming shaped articles from predetermined lengths of said web material, a source of supply of said web material, web feeding mechanism extending along a path of travel of said web from a point adjacent said source of supply and across said die to a web discharge station beyond said die, said web feeding mechanism comprising means to engage said web material adjacent the edges thereof for advancing said web across said die, a support attached to said frame and being movable relative to said frame in a direction transverse to said path of travel of said web, said web feeding mechanism being fixed to said support, means for operating said web feeding mechanism to feed a predetermined length of said web material into position over said die and means for moving said support and thereby said web feeding mechanism transverse said path of travel of said web to engage and disengage said web with said die.

3. In a machine for forming thermoplastic web material having a source of supply of said web material, a frame, a first die fixed to said frame, a second die movable on said frame and in line with said first die, said second die being movable along said line into and out of engagement with said first die, a feeding mechanism for advancing said web material in a path between said first die and said second die, said feeding mechanism comprising means to grip said web material adjacent the edges thereof, a support attached to said frame and being movable relative to said frame in a direction transverse to said path, said feeding mechanism being fixed to said support, and means for moving said support and thereby said feeding mechanism and said web transverse to said path to engage and disengage said web material with said first die.

4. In a machine for forming thermoplastic web material having a'source of supply of said Web material, a frame, a first die fixed to said frame, a second die movable on said frame into and out of engagement with said first die, a feeding mechanism for advancing said web material in a predetermined path through said machine whereby desired operations may be performed thereon, said feeding mechanism comprising means to engage said web adjacent the edges thereof for advancing said web across said first die, a support fixed to said feeding mech anism and being movably attached to said frame for motion in a direction transverse to said path, said feeding mechanism advancing said web between said'first die and said second die, and means for moving said feeding mechanism and said Web transverse to said support and thereby said predetermined path to engage and disengage said web material with said first die.

5. In a machine for forming thermoplastic Web material having a frame, a first die fixed to said frame, a second die in mating alignment with said first die and movably supported on said frame for movement into and out of mating engagement with said first die, means associated with said first die and said second die for forming shaped articles from predetermined lengths of said web material, a source of supply of said web material, web feeding mechanism extending along a path of travel of said web from a point adjacent said source of supply and between said first die and said second die to a web discharge station beyond said dies, said web feeding mechanism comprising means to engage said web adjacent the edges thereof, means for moving said second die into and out of mating engagement with said first die including means for locating said second die at a constant predetermined position spaced from said first die in which position a predetermined length of said web material is fed into position between said first die and said second die, a support for said web feeding mechanism, said support being pivotally attached to said frame for motion transverse to said path of travel of said web, and means for moving said support and thereby said web feeding mechanism transverse said path of travel of said web to engage and disengage said web material with said first die.

6. In a machine for forming thermoplastic web mate rial having a frame, a first die fixed to said frame, a second die in mating alignment with said first die and movably supported on said frame for movement into and out of mating engagement with said first die, means associated with said first die and said second die for forming shaped articles from predetermined lengths of said web material, a source of supply of said web material, a support extending along a path of travel of said web from a point adjacent said source of supply and between said first die and said second die to a web discharge station beyond said dies, web feeding mechanism extending along said path of travel and fixed to said support, means for moving said second die into and out of mating engagement with said first die including means for locating said second die at a position spaced from said first die in which position a predetermined length of said web material is fed into position between said first die and said second die, means for moving said second die into engagement with said first die after said predetermined length of said web material has been fed by said web feeding mechanism between said dies, means responsive to movement of said second die toward said first die for engagement therewith to move said support toward said first die to position said predetermined length of said web material on said first die, means for moving said second die out of engagement with said first die and means responsive to movement of said second die out of engagement with said first die for moving said support away from said first die to withdraw said predetermined length of said web material from said first die.

7. In a machine for forming thermoplastic web material having a frame, a first die fixed to said frame, a second die in mating alignment with said first die and movably supported on said frame for movement into and out of mating engagement with said first die, means on said first die and said second die for forming shaped articles from predetermined lengths of web material, a source of supply of web material, a support extending along a path of travel of said web material from a point adjacent said source of supply and between said first die and said second die to a discharge station beyond said dies, said support being pivotally connected at one of its ends to said frame and operatively connected adjacent its opposite end to said second die, web feeding mechanism extending along said path of travel of said web material and fixed to said support and means for moving said second die into and out of mating engagement with said first die including means for locating said second die and said support at a position spaced from said first die in which position a predetermined length of said web material is fed into position between said first die and said second die, means for moving said second die and said support from said predetermined position into engagement with said first die after said predetermined length of said web material has been fed by said web feeding mechanism into position between said dies, and means for moving said second die and said support out of engagement with said first die.

8. In a method for forming shaped articles from a thermoplastic sheet, said method comprising the steps of intermittently feeding a continuous web of thermoplastic material through a heating zone, intermittently feeding said heated thermoplastic material in a path from said heating zone to a forming zone and, after said thermolastic sheet is shaped, moving said shaped thermoplastic material in a direction transverse to said path to remove said shaped material from said forming means and thereafter removing said shaped material from said forming zone, said material being gripped adjacent the edges thereof to impart said motions thereto and to restrain said material during said feeding, moving and removing steps.

9. In a method for forming shaped articles from a thermoplastic sheet, said method comprising the steps of feeding a continuous web of thermoplastic material in a path from a source of supply through a heating zone and into a forming zone, and, when a predetermined length of said web material is in said forming zone, interrupting said feed and moving said predetermined length of web material in a direction transverse to said path and into contact with a forming die, forming a shaped article in said length of web material and, thereafter, moving said length of web material, with said shaped article formed therein, out of contact with said forming die and back into said path, and, with said length of web material with said shaped article formed therein out of contact with said forming die, recommencing said feed in said path to discharge said shaped length of web material from said forming zone and, as said length is discharged, delivering a following predetermined length of said web material into said forming zone, said material being gripped adjacent the edges thereof to impart said motions thereto and to restrain said material to prevent shrinkage thereof during said feeding and moving steps.

References Cited in the file of this patent UNITED STATES PATENTS 544,665 Draher Aug. 10, 1895 1,589,176 Hubbard June 15, 1926 2,229,613 Strauch Jan. 21, 1941 2,522,956 Middleton Sept. 15, 1950 2,796,634 Chellis June 25, 1957 FOREIGN PATENTS 741,040 Great Britain Nov. 23, 1955 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,036 336 May 29, 1962 Gary G. Menkel It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 42, before "feeding" insert support and thereby said lines 43 and 44, strike out "said support and thereby column 6, line 45, for "Aug. 10, 1895" read Aug. 20, 1895 line 48, for "Sept. 15 1950" read Sept.

Signed and sealed this 22nd day of January 1963.

(SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents 

